What do folks make of this one...

[Jamey K]

I have heard a captain say "the last one down please free up the anchor" (and make sure you are the last one (or last team), etc.). I have never heard a captain say to free up the anchor at the beginning of the dive. Or at least he/she may have meant to free it from such obstruction that at least it could be retrieved (like if the chain was wrapped around something), but not to put it into the sand at the start of the dive. There was some definite communication break-down here in my humble opinion. I suppose no one will really know. But I do agree that there were a lot of mistakes. For someone to put the anchor into the sand at the beginning of the dive was not a good idea and that should not have been done, no matter what their supposed instruction was from the captain. But hey, what do I know? I am just like everyone else on this blog. Just stating an opinion, partly based on experience and partly based on what others are saying. (Jamey).

 

[Diver0001]

LESSONS LEARNED

The lessons learned from this are many:

1) If you are moving the anchor to free it from obstructions it, make sure it bites into to sand.

2) Since we had planned to return up the anchor line, it may have made more sense to move it at the end of the dive, not the beginning. The downside here is that had we failed to return, a subsequent dive to free the anchor may have been needed.

3) Some teams saw the anchor was skipping and decided to continue their dive. It would have been better for them to ascend up the skipping anchor and alert the boat.

4) Our 3-foot (1M) safety sausages are only really useful with little or no swell. 6-foot sausages would have been better here (but would still not have been visible to our dive boat).

5) The boat didn’t notice they were drifting. A portable GPS, or an alarm on the boat GPS would have helped here

6) Sometimes it’s better to cut decompression (or safety stop) short or omit it altogether and surface earlier. Had we not done so, who knows how far we would have drifted, and if we would have been within range of a fishing boat to come to our rescue.

7) Check your safety sausage for leaks regularly and fix them (I think the reason one team’s sausage didn’t inflate correctly).

8) Giving accurate maximum runtimes to the boat captain is a valuable logistical and safety tool.
We learned a lot from this experience, and hopefully you can too. Dive safe.

Well... the story sounds embellished to me, but I'll give a couple of opinions based on the lessons learned.

I'm not sure how they do things in California, but over here, the up-line is rigged separately from the boat and the boat will generally either use a gps based auto-pilot to remain on station or anchor nearby. In the latter case a zodiac will be employed for picking up divers. The anchor is physically tied to the wreck by the first divers to descend and a small dsmb which is attached to the anchor is partially inflated as a visual aid to finding it again. If divers need to lay out a guide-line, which is the norm here, then they start their lines within a few meters of the anchor. The last divers to ascend untie the anchor and lay it off the wreck for retrieval. The little DSMB is then launched to the surface as a sign to the boat that the anchor is loose. Normally this will be done by the crew unless otherwise agreed upon.

As for dive plans, communication with the boat etc. In conditions with heavy surface current having the right signalling tools (visual, audio and a lifeline -- all in proper working order) are not "oh yeah" items that you think about AFTER something happens.

If there is a risk of drifting off a wreck and having to ascend and/or do deco mid-water then you don't cut your deco short .... you SHORTEN THE DIVE so you don't have to. This advice (#6) demonstrates a severe lack of proper planning and an apparent inability to account for all the risks. As an aside to this, I've seen someone in the past launch a blob and then tie it off to the wreck to use as an improvised ascent line so they didn't drift off the wreck at all. It worked. They had to cut the line once they were picked up, obviously, but losing 30 or 40m of line is a lot better than drifting a KM off off a wreck.

R..